Example scripts

For a detailed tutorial on how to use the package, check out these papers:

The following Python scripts demonstrate basic and advanced functionality of QuSpin. In many cases, we have chosen to exhibit QuSpin’s functionality, and there may exist a more efficient approach to obtain the same result using QuSpin.

To run the example scripts, besides QuSpin, you have to also install matplotlib (e.g. by using pip or anaconda):

Getting started

Basics of QuSpin basis objects, download script

Exact Diagonalisation of Spin Hamiltonians, download script

User-defined ODEs: the Gross-Pitaevskii Equation and Nonlinear Time Evolution, download script

Parallel computing in QuSpin

Parallel Computing in QuSpin, download script

Basic usage

Non-interacting systems

Quantised Light-Atom Interactions in the Semi-classical Limit: Recovering the Periodically Driven Atom, download script

Free Particle Systems: the Fermionic SSH Chain, download script

Optical Bloch equations: Lindblad dynamics using the matvec function, download script

The Spectrum of the Transverse Field Ising Model and the Jordan-Wigner Transformation, download script

Interacting systems

Fermi-Hubbard model without doubly-occupied sites, download script

Hexagonal Lattice: Fermi-Hubbard model [courtesy of A. Buyskikh], download script

Heating in Periodically Driven Spin Chains, download script

Integrability Breaking and Thermalising Dynamics in the 2D Transverse-Field Ising Model, download script

Many-Body Localization in the Fermi-Hubbard Model, download script

Adiabatic Control of Parameters in Many-Body Localised Phases, download script

Out-of-Equilibrium Bose-Fermi Mixtures, download script

Majorana Fermions: SYK Model, download script

The Bose-Hubbard Model on Translationally Invariant Ladder, download script

Advanced usage

Quantum scars Hamiltonian: spin-1/2 system with Hilbert space constraint, download script

Spin-1/2 system with sublattice particle consevation, download script

Applying symmetries to reduce user-imported bases using QuSpin, download script

Autocorrelation functions using symmetries, download script

Direct Calculation of spectral functions using symmetries, download script

Gell-Mann Operators for Spin-1 systems, download script

Majorana Fermions: Spinless Fermi-Hubbard Model, download script

Kitaev’s honeycomb Hamiltonian in vortex sectors given by the plaquette operators, download script

Algorithms and routines

Monte Carlo Sampling Expectation Values of Obsevables, download script

Efficient time evolution using the omp-parallelized expm_multiply_parallel, download script

Lanczos module: time-evolution and ground state search, download script

Lanczos module: finite-temperature calculations, download script

Liouville-von Neumann Equation using the MKL-enhanced Sparse Matrix Product [courtesy of J. Verlage], download script